usb: chipidea: add chipidea revision information

Define ci_get_revision API to know the controller revision
information according to chipidea 1.1a, 2.0a and 2.5a spec.
Besides, add one entry at struct ci_hdrc to indicate revision
information, it can be used for adding different code for
revisions, eg kinds of errata.

Reviewed-by: Stefan Agner <[e-mail]>
Signed-off-by: Peter Chen <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/chipidea/bits.h

···
 
 #include <linux/usb/ehci_def.h>
 
+/*
+ * ID
+ * For 1.x revision, bit24 - bit31 are reserved
+ * For 2.x revision, bit25 - bit28 are 0x2
+ */
+#define TAG		      (0x1F << 16)
+#define REVISION	      (0xF << 21)
+#define VERSION		      (0xF << 25)
+#define CIVERSION	      (0x7 << 29)
+
 /* HCCPARAMS */
 #define HCCPARAMS_LEN         BIT(17)
 

drivers/usb/chipidea/ci.h

···
 	CI_ROLE_END,
 };
 
+enum ci_revision {
+	CI_REVISION_1X = 10,	/* Revision 1.x */
+	CI_REVISION_20 = 20, /* Revision 2.0 */
+	CI_REVISION_21, /* Revision 2.1 */
+	CI_REVISION_22, /* Revision 2.2 */
+	CI_REVISION_23, /* Revision 2.3 */
+	CI_REVISION_24, /* Revision 2.4 */
+	CI_REVISION_25, /* Revision 2.5 */
+	CI_REVISION_25_PLUS, /* Revision above than 2.5 */
+	CI_REVISION_UNKNOWN = 99, /* Unknown Revision */
+};
+
 /**
  * struct ci_role_driver - host/gadget role driver
  * @start: start this role
···
  * @supports_runtime_pm: if runtime pm is supported
  * @in_lpm: if the core in low power mode
  * @wakeup_int: if wakeup interrupt occur
+ * @rev: The revision number for controller
  */
 struct ci_hdrc {
 	struct device			*dev;
···
 	bool				supports_runtime_pm;
 	bool				in_lpm;
 	bool				wakeup_int;
+	enum ci_revision		rev;
 };
 
 static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci)

drivers/usb/chipidea/core.c

···
 	return 0;
 }
 
+static enum ci_revision ci_get_revision(struct ci_hdrc *ci)
+{
+	int ver = hw_read_id_reg(ci, ID_ID, VERSION) >> __ffs(VERSION);
+	enum ci_revision rev = CI_REVISION_UNKNOWN;
+
+	if (ver == 0x2) {
+		rev = hw_read_id_reg(ci, ID_ID, REVISION)
+			>> __ffs(REVISION);
+		rev += CI_REVISION_20;
+	} else if (ver == 0x0) {
+		rev = CI_REVISION_1X;
+	}
+
+	return rev;
+}
+
 /**
  * hw_read_intr_enable: returns interrupt enable register
  *
···
 	/* Clear all interrupts status bits*/
 	hw_write(ci, OP_USBSTS, 0xffffffff, 0xffffffff);
 
-	dev_dbg(ci->dev, "ChipIdea HDRC found, lpm: %d; cap: %p op: %p\n",
-		ci->hw_bank.lpm, ci->hw_bank.cap, ci->hw_bank.op);
+	ci->rev = ci_get_revision(ci);
+
+	dev_dbg(ci->dev,
+		"ChipIdea HDRC found, revision: %d, lpm: %d; cap: %p op: %p\n",
+		ci->rev, ci->hw_bank.lpm, ci->hw_bank.cap, ci->hw_bank.op);
 
 	/* setup lock mode ? */